So that the energy dissipated by electrical components on a PC board can be conducted away as best as possible, PC boards are glued flat on a cooling body by means of a suitable adhesive. In this case the PC boards can consist of a ceramic substrate and have a surface of for example 6.times.4 inches. The cooling body located underneath the PC board may consist of an aluminum plate or the like, which is adapted to the surface of the glued-on ceramic PC board.
In these connection arrangements there is, on the one hand, a requirement for the adhesive to be sufficiently resilient so that it can even out the different degrees of thermal expansion of the ceramic substrate and the aluminum plate by its resilience. On the other hand, however, the adhesive should nave the best possible thermal conductivity, so that the heat given off by the structural components (energy dissipation) can be conducted away to the aluminum plate in the best possible way, so that the respective electric components do not heat up too much. To give the adhesive improved thermal conductivity, it is possible to admix with it, for example, metal particles, ceramic particles or other materials with a high degree of thermal conductivity. However, the resilience of the adhesive is reduced in the same degree as the amount of thermally-conductive particles present in the adhesive is increased. This results in requiring the adhesive layer to be thicker than that of a highly resilient adhesive which, however, shows very poor thermal conductivity. But the thicker adhesive layers of the loaded adhesives counteract good thermal conductivity. Furthermore, the adhesives enriched with thermally conductive particles have noticeably less adhesiveness than adhesives which have not been "loaded".